Table 1.

Predicted location of residues in the 3-MSD conformation of the gp41 of HIV-1 clades A to D in the virion or cell membrane

	Position	Number of residues
Major ectodomain	512–690	179
MSD 1	691–700	10
Turn	701–702	2
MSD 2	703–712	10
Minor ectodomain (external loop)	713–753	41
MSD 3	754–763	10
Internala	764–863	100

^aComprises 30 residues analyzed here, and 70 not analyzed.